Calling party identification for automatic telephone systems



Oct. l0, 1950 GQ DEAKIN CALLING PARTY IDENTIFICATION FoR AUTOMATICTELEPHONE SYSTEMS 7 Sheefs-Sheet 1 Filed April 4, 1944 (ITSM MQ m@ .m KM D M m e 6 Oct. 10, 1950 G. DEAKIN CALLING PARTY IDENTIFICATION FOR,AUTOMATIC TELEPHONE SYSTEMS '1 sneek-sheet 2 Fil-d April 4, 1944 ms S INVEN TOR. 6em/d Deakin AGENT Oct. 10, 1950 G. DEAKIN CALLING APARTYIDENTIFICATION FoR AUTOMATIC TELEPHONE SYSTEMS 7 Sheets-Sheet 5 FiledApril 4, 1944 HTL IN VEN TOR. Gera/d Dea/fin AGENT 7 Sheets-Sheet 4 G.DEAKIN CALLING PARTY IDENTIFICATION FOR A'AVAVAV A'YA'A' AUTOMATICTELEPHONE SYSTEMS INVENTOR. 6em/d Dea/fm BY AGE/vr Oct. lO, 1950 FiledApril 4, 1944' SME NE El m E M. mw HJ w m m @PM l I I .WMl 4 i rii 1 NEn m A ./T )Er Oct. 10, 1950 G. DEAKIN CALLING PARTY IDENTIFICATION FOR-AUTOMATIC TELEPHONE SYSTEMS Filed April 4, 1944 '7 Sheets-Sheet 5 mmm.

@et Y10; i950 G. DEAKIN CALLING PARTI IDENTIFICATION Foa AUTOMATICTELEPHONE SYSTEMS Filed April 4. 1944 7 Sheets-Sheet 6 INVENTOR. 56m/d@eq/fm @S @SNE Mok@ @et 'E09 1950 G. DEAKIN CALLING PARTY IDENTIFICATIONFoa AUTOMATIC TELEPHONE SYSTEMS 7 sheets-sheet '7 Filed April 4, 1944Patented Oct. v10, 1950 CALLING PARTY IDENTIFICATION FOR AUTOMATICTELEPHONE SYSTEMS Gerald Deakin, New York, N. Y., assignor toIntei-national Standard Electric Corporation, New York, N. Y., acorporation of Delaware Application April 4, 1944, serial No. 529,506yzo claims. (ci. 17a- 8.5)

This invention relates to automatic and semi- .automatic telephoneexchange systems and more particularly to party line measured serviceidentilication.

An object of my invention is the provision `of means for the automaticidentification of a calling party line station by a register when thecalling party dials the lirst digit of a wantedrsubscribers number.

A further object is the provision of automatic means whereby when aparty line ,Station initiates a call a distinctive class of servicesignal is transmitted to the register which is automatically convertedfrom its normal condition for dealing with main line calls to a modiedcondition for handling party line calls.

In a preferred arrangement the register, after being taken into use by aparty line call, sends back to the calling circuit over the test wire asignal, for example a distinctive potential, characteristic of theidentity of the calling party line, A party line identification circuit,which and serves a group of party lines, associates itself with thecalling party-line and in response to the distinctive potential connectsthe individual service meter and lirst identication line finder ter'-minals of the calling party line station to the l calling party linecircuit.V The before-mentioned identification potential is alsoautomatically connected over the test wire to the test terminal of thecalling party line station in the bank of the first identificationfinder switch, whereby when a toll operator or automatic ticketer or thelike searches for the number of the calling station the number obtainedwill always be that of the calling station.

These and other objects and features of my invention will `be clear froma reading of the following detailed description taken in conjunctionwith the accompanying drawings which illustrate a preferred embodimentof my invention.

In the accompanying drawings:

Fig. l is a block schematic drawingv showing sufficient of the layout ofan exchange to give a clear understanding rof the present invention;

Fig. 2 is a circuit diagram of a four party line `station circuitprovided with rectifier dialing;

Fig. 3 is a plan view of a rectier dial showing the finger hole plateand finger stop;

. Fig. 4 is an elevation partly in section taken on the line 4-4 of Fig.3;

Fig. 5 is a section taken on the line 5 5 of Fig. 6`is a section takenon the line 6--6 of Fig. 4; Y

Fig. T1 shows-V a detail of the spring nest in the A 2 tion subscribersline circuit with individual meters;

Figs. 10 and 11 (Fig. 11 placed below Fig. l0) show a circuit diagram ofa register adapted for four-party line rectifier dialing; and

Fig. 12 shows a circuit diagram of a modified arrangement for thepulsing relays in the register.

Referring first to Fig. 2, the station circuits A, B, C and D showntherein are apart from the rectifier dials R ofthe usual type. Therectier dials which will be described later in connection with Figs. 3to 7 each include a rotating rectilier R. and a home contact spring nestS. The operation of the rectilier dial from a circuit point of View isas follows: When the 'finger wheel is moved oli normal a pin P3 allowsspring B to break contact with spring C which removes a short circuitfrom the rectifier R and to make contact with spring A which shortcircuits the induction coil and transmitter. Pin Pl causes spring F tobreak contact with spring G until shortly before the first finger holereaches the finger stop; in other words, the line circuit is momentarilyopened each time the finger wheel isl turned to the linger stop. Whenthe' finger wheel isreleased, the rectilier R makes one-half of arevolution for each linger hole passing the linger stop but before thelast linger hole passes the finger stop the pin Pl again opens contactbetween the springs F and G thereby momentar- 'ily opening the linecircuit which causes the digit change-over in the register to takeplace. As will be clear from the subsequent description of the rectifierdial, the rectifier is always returned to its predetermined position ofpolarity. Thus, should an odd digit be dialed the rec- 'tier is given ahalf revolution to restore it to its normal position while contactbetween springs F and G is open.

From what has been said above it will be seen that when the digit 1 isdialed the initial closure of the line through the rectifier R in itsnormal position sends the first pulse to record the digit 1 and thatwhen the finger wheel is released the circuit is .opened for thechangeover before the rectilier reverses the current.

The polarity of the first pulse is determined by the manner in which thestation is connected to the line.

Contact P2 is used only at stations C and D and its purpose is to causethe transmission of a second positive or negative pulse when the dial ispulled to the linger stop.

When the finger wheel is moved off-normal with pin P2 in position, pinPI first opens contact between springs F and G, but shortly afterwardsthis contact is momentarily closed by pin P2 engaging the lip Il ofspring G. Springs F and G are again permitted to make contact when 3 vthe wheel has been moved just less than two linger hole spaces and thepin P2 rides over lip I8. By this means two pulses of the same polarityare sent to the register as will be described later. The registerrecords the first digit on the rst pulse but as polarity is notchanged.'

the second pulse merely indicates to the register the identity of thestation and does not add a digit to the number dialed. The stations Aand B are identical to normal stations except that station B is reversedwith respect to station A as regards its connection to the a and b wiresextending to the line circuit. Stations C and D are connected in thesame manner as stations A and B, respectively, but in addition theirrectier dials are equipped with the pin P2.

The construction of a suitable rectifier dial is illustrated in Figs. 3to 7 land will now be described. Referring first particularly to Figs. 4and 5, the dial consists of two main parts, an upper part I housing thehome Contact nest HC and a lower part 2 housing the rotating rectiiierS.

lIn the upper housing I is mounted a finger wheel 3 provided with theusual iinger holes and attached to a shaft I which rotates in a sleeve 5in the housingl I when driven by a coiled spring 6, one end of which isattached to the finger wheel 3, while the other rests in a groove in thehousing part I. A segment 'I is attached to shaft 4 by nut 8. A pawl Siis pivoted to the segment 'I and tends to engage the teeth of a ratchetwheel IB under the tension of a spring Ia.

Ratchet wheel II] and a gear wheel II are attached to each other androtate freely on the lower extension of shaft Il. They are held inposition by the i-lat head IIa of a bearing pin I2 when the lower part 2housing the rectifier unit is mounted in position. Ratchet wheel IB hasa number of teeth corresponding to the number of positions of the ngerwheel 3. Every other tooth is relatively long (in a radial sense). Whenthe finger wheel 3 is in its normal position one edge of the segment 1rests against a back stop I3 formed in the housing I and a raisedsurface I4 on the inner periphery of the housing I adjacent the stop I3lifts the pawl 9 so that it engages only the deep teeth of ratchet I0.

When the nger wheel 3 is rotated by the user, the segment l movesclockwise and when it has moved an angular distance equal to about onenger hole spacing the raised surface It no longer bears on the pawl 9and the latter rotates slightly about its pivot so as to engage both thelong and the short teeth of the ratchet wheel ID. Should the iingerwheel beturned a distance equal to ve iinger holes, that is, should thedigit 3 be dialed, since there is a space equal to two nger holesbetween the hole number I and the iinger 'stop I9, the pawl 9 willengage a short tooth. When the nger wheel is released the spring 6 willrotate the ratchet wheel ID counterclockwise. As the segment 'Iapproaches its home position, the pawl 9 engages the raised surface I4and thus disengages the short tooth but reengages the next long toothjust before the segment 'I comes to rest against the back stop I3. Theobject of this arrangement is to insure that the rectiier S alwaysreturns to its `predetermined position of polarity.

The home spring nest consists of five springs A, B, C, and G, Figs, 2and 5, mounted in a block Sil of insulating material iixed to thehousing I. Two pins PI and P3 are mounted on the segment "I in suchposition that when the finger wheel is moved off normal, pin PI vopensthe contact between springs F and G, whilst pin P3 opens the contactbetween springs B and C and permits Contact to be made between springs Aand B. A third pin P2, which is readily detachable, is used at'stationsC and D and is mounted on segment 7 in such position that it engagesspring G shortly after pin PI opens springs F and G. The segment 'I isof insulating material.

Assume now that the digit 1 is dialed at any station. When the ringer isplaced in hole number I, Fig. 3, and the finger wheel is moved oinormal, pin PI engages the tip I5 of the extension of spring F, Figs. 4and 7, and breaks the normal contact between springs F and G. Spring Fis cutaway at its lower edge and provided with an inclined lip I6, asshown in Fig. 7. When the hole number I has been moved an angulardistance less than two finger hole spaces, pin PI rides `over the lip I6and disengages the spring F, so that when the finger reaches the fingerstop I9 contact between springs F and G is again made. The three homecontact springs A, B and C are shown in their normal positions in Fig.5. When segment is moved off normal, pin P3 disengages spring B therebycausing contact to be broken with' spring C andrmade with spring A. lThesprings A, B and C remain in this position until the dial returns tonormal.

When the finger wheel 3 is released, after it has moved aboutthree-quarters of a nger hole space, pin PI reengages the projecting lipI6 of spring F and again opens the contact between springs F and G. Whensegment l reaches its normal position against the back stop I3, contactbetween springs F and G is restored,

As already stated when the dial is used at stations C and D pin P2 isadded. This pin P2 engages the lower lip I'I of spring G (shortly afterpin PI opens the Contact between springs F and G) and causes spring G toremake contact with spring F for a short period. Spring G is cut away atits lower edge and formed with an inclined lip I8 similar to the springF. When the pin P2 rides over this lip I8 shortly afterwards, contactbetween springs F and G is broken again before pin PI allows springs Fand G to make contact just before the second position is reached. Thuswhen the pin P2 is used, two positive or two negative impulses are sentduring the initial movement of the nger wheel and depending upon theconnections to the a and b wires.

The lower part 2 houses the rectier discs S, Figs. 4 and 6. These areassembled on a bushing 2l of insulating material. Brush 20a is clampedagainst the rectifier disc on one side of the rectier unit and brush 20his clamped against the disc on the other side by means of nuts 22. Abearing pin I2 which passes through the bushing 2| has screwed to it agear wheel 23 and rotates in bushings 24 attached to the upper and lowercovers of the rectier housing 2. The bearing pin I2 is grooved so thatwhen it is slipped through the bore oi the bushing 2I the rectierassembly S and brushes 20a and 2Gb rotate with the bearing pin I2 andthe gear wheel 23.

The upper and lower brushes 20a and 20h rub against collector rings 24aand 24D mounted on the inside wall of the housing 2 as shown in Fig. 6.The external connections are connected to the collector rings 24a and24h. AGear wheels II and 23 are interconnected by pinions 25 which areattached to each other and held in position by a bearing pin 26 mountedin the upper end of the housing portion 2. The ratchet and gear Wheelsmagma unit S is in the position shown in Fig.6. The. ratioofthe-'various gearsfissuch thatthe recti- 'er unit S` makesv onecomplete revolution when the finger wheell 3 :moves an `angulargdistanceequalitotwofiinger hole spaces. -V

The setting of brush-es 20a and 20h, Fig. 6, is such that when theyengage the insulating surfaceseZ'IJbetweenthe collector rings 24a and24h as'position ofithe ratchet wheel passesthe normal` position 1 on thereturn journey,` the .pin P1.enlf gages lip I6 of the spring' `Fandopens the con-1- tact-between springslF and Thusthe lcontact betweenthese 'springs is opened* before the brushesl 20a and 2.05 make contactwithI the succeeding collector rings.-A y y l 1Asspeedcontrolfofa-rectiiier dialV is not critical it-is suiiicient' to weight thebrushes 20a and 20h at their ends so that they act both asv governorwings as well asl collector brushes.

The method of party line dialing according to my invention will rstbedescribed in a general way' as applied to a m'ultiepotential telephoneeX- change system of the kind fully disclosed in my copendingapplication Serial` No: 521,160, filed February 5, 1944.

Each station of a tour-party line is provided with a set of terminals'in the banks of the first line finders and' iinal's and in the banks offirst identification finders (see Fig. 9) Each station has itsindividual negative PNv potential connected toV its test terminal T overthe back con-v tactof a cut-off relay CORI.v provided with an individualservice meter SM and when a station dials, its service meter and onlyits service meter i'sconnected tothe c wire by a relay PSR which isindividualto each station and which relayfalso connects the T termial ofthe first identiiication finder and only that T terminal to the testwire of the line circuit.` Thus when service meter current is placed onthe cA wire thev service meter SM of the calling station and only thecalling station is energized andwhen the numerical positiveidentification potential PI is placed on the test wire, the nurn-` berof the calling station and only the calling rstation is passed back tothe identifying operator in Finally, the ncegative' serviceclasspotential PSv Each station is connected tothe T., terminal of theiirst identithe part of a subscriber who may know suflicient` of theoperation of the system to reverseV the wires at his station and therebycause a call to be charged to another station.

The operation offthel circuits will now be de scribed in detail. J Y

Y When any calling subscriberremoves his' reY ceiver, relay-LR, Fig. 9,Ain the line circuit opf crates over-'the station loop, closes anobvious? circuit for' cut-offrelayv CORI andgrounds the, associatedR-link starter andA Chooser circuit which selects an idleR-link -(Fig..=1"), a registeri finder associated with which connects up. an"

idle' register anda'- B-link :finder Yassociated with 6i. which.selects;V arr; idle B=link-.haying associated therewith a rst groupselector anda second line finder. The secondfline finder hunts for anidle rst. line finder` having; access tothe calling line.

, Relay. CORI, Fig. 9, disconnects the negative. in-

dividual. PN potentials. from the four testterminals and. in. placethereof` connects the test terminal T, ofvv station A. to the negativecalling line potential rPCvwhich, is applied over the lower backcontacts of .cut-,off relay COR. Thus; it will be seen thatuwhen a calloriginates. vfrom any station the terminals of. station A. are alwayspicked up by'anidlelrst'lineflnder which extends' the call oyer'aB-'linkand-fan.. R-link toa, register as fully described in my copending:applicationSerial No. 521,160 led February 5, 1944.

When the i'irst linev finder picks up the calling line, thecut-oilfrelay'CORv operates inthe usualv manner over the cy/ire,.disconnectstheline re. lay LR from the calling line and the callinglineVv potential PC from the test terminal T and theot wire, and inplace thereof connects to the t wire'V over back contacts of relaysiPSRI', IPSRZ, PSRS,` and PSR4, a negative service classpotential PS2.which potential is extended at this stageto the register and not to-atrunk to an operator. 'I his particular lpotential is used for y twopurposes; rst to indicateto the register a; call coming from afour-party line, and subsequently-to indicate. to an operator thatstation B. is calling.

The register shown. in.Figs. 10 and l1 is generally similar to theregister described in my copending application last referred tov andonly that part of the circuit has been shown which` relates.` to partyline rectier dialing since, it .isv

believedthat this will enable a clear understanding of the presentinvention Ywithout the intro,-v duction of unnecessary complication.When the calling line is. picked up, relaysi RAR and RBR releaseand;operate, respectiyely, as described in the copending applicationlastreferred to and relay HR operates over a circuit extending fromYbattery, back contacts of.' relay RIR, front contacts of relay RBR` andupper winding of' relay HR. `Relay'lrIR locks up overl both, itswindings and Vthewcallrig pline. Atthe samevinstant the potential PS2derivedover backcontacts-of re,y lays' PSRKE, PSRS, PSRZ, APSRI',rontcontacts. of` relay COR, and' front contacts-.of relay CORI is extendedvover a first line finder, Isecond line finder, B-link, R-link, brush ofthe register finder andupper back contactsof :relay ER, Fig."10, to thegrid of` tube V2A. The pair of tubes- YVIA, V2A andthe gas valve GV,arer arranged 1 and operate inthe manner-'fully described in copendingapplication Serial Nos. 485,827,l now Patent-N0. 2,354,682, andy521,160, VnowPatent No. 2,484,060, filed May', 1943, and February5,1944, respectively. Since the ygrid of tube VIA is connected 'topotential PS2 which is the potential which indicates a four-party line,gasv valve GV rires and operates relay GVR which in turn operatesrelayGSR. Relay GSR 4closes an `obviouscircuit for relay ER which locks upand disconnects the twire from the grid oftube V2A andin place. thereofconnects itto the low resistance upper winding of ,relay FRoverj aback'V contact of relay FR. -`Shouldthe register .not` nd potentialPSZon ,the t wire,llgas valve GV will'not re, relayffER-i-s not operated,the reg= ister makes no attempt to identify `the calling Y line and theconnection -is set up in a normal manner. The t wire may, ofcourse, beconnected'to: the grids ofiother tube circuits :set for 7 other dassidentifications to which the register may adapt itself.

Upon energization, relay HR closes a circuit for a slow release relayRIR which places battery on both windings of a differential relay DR,the windings of which are so arranged that the relay does not operate aslong as both windings are energized over back contacts of impulsingrelays Upon energization of relay RBR a circuit is also closed over thedialing tone interrupter DTI and the dialing tone transformer TT, andwhen the relay HR operates the dialing tone is sent over the subscribersline. The circuit remains in this condition until theY subscribercommences to dial.

As already explained, the four stations of a party line are identied bythe character of the pulse or pulses sent when the dial is pulled to thefinger stop. The identifying pulses are asfollows:

Station A, Station B, Station C, StationAD,

By a positive pulse is meant current ilowingfrom the b wire to the awire and by a negative pulse is meant current flowing from the a wire tothe b wire.

The register circuit is provided with four rst counting relays CIAR,CIBR, CICR and CIDR. The first relay CIAR is energized when station Adials, the second one CIBR is energized when the station B dials, thefirst and third CIAR and CICR are energized when station C dials and thesecond and fourth CIBR and CIDR are energized when station D dials.

When station A dials, as the finger wheel of the rectifier dial is movedfrom its home position the pin P3 opens contacts B and C (Fig. 2) andremoves the short circuit from the dial rectier R and the line circuitis momentarily opened. Relay HR releases but not the slow release relayRIR. When the line circuit is closed again to send one positive pulseover the line, the line circuit is again closed, this time through therectifier R in the subscribers set and current flows in such a directionas to energize polarized relay PR(-|), Fig. 10. This cur rent flows fromthe 400 cycle, 50 volt source over a resistor R1, a guard lamp GL, backcontacts of relays HR and RAR, a wire, dial rectifier R at thesub-station, b wire, back contacts of reone positive pulse one negativepulse two positive pulses two negative pulses lays RAR and HR, rectifierSI and the left-hand winding l of relay PR(-l). Relay PR(-|-) operatesand opens its back contacts thus opening one winding of diierentialrelay DR and causing it to operate. Relay PR(\) also removes a shortcircuit from relay CIAR and relay NR both of which operate. Relay DRenergizes relay R3R which closes a circuit for relay R4R. Relay DRcompletes a holding circuit for relay RIR over a back contact of relayHR. When relay R4R pulls up it closes a circuit -for relay DTR whichlocks up and removes dialing tone from the subscribers line. A

RelayCIAR locks up in series with a relay SR to a -front contact ofrelay RlR and relay NR locks up over front -contacts of relay CIAR.

If station B -dials the same sequence of operations takes place with theexception that responsive'to the transmission of a negative pulse overthe line the negatively Vpolarized relay PR(-) breaks its back contactand short circuits are removed from the relays CIBR and time,'a circuit,is established over one winding of relay DR, a back contact of relayCIBR, frontl contacts of relay CIAR, back contacts of relayv NR, backcontacts of second counting relay CR2, back contacts of relay OR andrelay CICR for relay CICR which locks up in series with relays SR.Similarly, when station D dials the two negative pulses result in theoperation and locking up of relays CIBR and CIDR responsive tosuccessive operations of the negatively polarized relay PR(-).

When the nger wheel is released, alternative positive and negativepulses energize the polarized relays PR(-l) and PR(-) and successivelyenergize the counting relays CRZ to CRIU which lock up over resistorsR4.

It will be noted that when the dial rectier at the calling party linestation is in a position to allow a positive pulse to pass, the ringersat the other party line stations on the line are effectivelyshort-circuited by the rectifier as regards this positive pulse, butduring the time that the recf tiiier is passing this positive pulse,which actually consists of an integrated group of short positive halfcycles, the simultaneous vcomplementary group of negative half cycles isnot short-circuited by the rectifier and unless provision is made willpass through the ringers and condensers at the other stations. vWhen therectier atrthe calling station reverses and passes a negativel pulse,therringers receive the integrated groups of positive half cycles, andso on. Since these pulses arrive at a speed of 2O to 40 cycles, theringers will chatter when the current is of sufficient strength. This isprevented by effectively shortcircuiting all pulses so far as theringers are concerned.

Relay PR(-i), break its back contacts only when it receives positivepulses and relay PR(-) is polarized so as toA break its back contactonly when itreceives nega-l tive pulses. Each of these relays has a highrei sistance winding I anda low resistance winding 2.v

vand a' rectier is inserted inA series with each winding. Assuming thatthe rectifier at the calling'station is in position to pass a positivepulse, this pulse will pass through rectier SI and winding l of relayPRH-),but rectier S2 is so polarized'as to-prevent the positive pulse ofcurrentfrom passing through winding I ofrelay PR(-). When the armatureof relay PR(-|-) makes its front contact it connects the lower end oflow resistance Winding 2 of relay PR(-) to ground.

The other end of this winding is connectedl through rectifier S4 totheline and the sourcefof alternating current through resistance Rl.-Recter S4 is polarized to pass only negative pulses. Thus the integratedpositive half 'cycles from the generator pass through the dial rectierat the calling station and through rectier Sl to ener.-

gize relay PRH-L while the negative half cyclesv pass through. therectifier S4 and winding 2 of relay PR(- As relay PR(-i) is quickacting'. it closes the negative pulse shunt through relay Betweenpositive pulses, however, thev line1 Thusl when relayv PR breaks itsback contacts for the'secondv `Fig. 10, is so polarized as toiAsufficientfcurreni'. forfthemto chatter. The nega;

tivefpulse also tends to force'the armatureoi" relay PRI-J against its'backcontact whereby a push-pull action of the relays PR(-`I-) -andPR(-)isobtained; Whenthe dial rectier at the calling station reverses itspolarity, the negative pulse operates relay PR over rectierSZ and `relayLPRiH) closes a shunt for the contemporaneouspositive pulse overrectiiier S3 and winding 210i relay PR iFig. lf2 shows a modifiedarrangement of the stepping relays' 1PR(I-), PR() in which the push-pullaction of these relays, which is not necessary'ior slow or moderatespeed dialing, Iis not employed. In this arrangement the relays are onlyprovided with a Single winding. When a Apositive pulse passes throughthe dial rectier at the substation, relay PR`(I-') voperates throughrectifier S5 and connects rectifier'Sl to the generator throughresistances R8 and Rl so as to vabsorb the Ysimultaneous negativetpulse. `When a fnegative pulse `passes through thedial rectifier, relayFR operates 'through rectiiier Se and connects rectifier fito fthegenerator. This circuit smay sbe more effectiv'ein shunting outsensitive-ringers because its-excludes the inductive Awinding cfa relayand resistance R8 may be 'made aslow asnecessaryiand even entirelyomitted in Aview-of.theproyisionfofresistor R1.

. Whenitheseries of'pulses-ce'ase;the line'circuit is .fagainmomentarilyopened byzthe pin PI of the fdi'alfj ust before Yiticomes'tp rest, ashas already been explained tin the: preceding description oftheconstruction of the riial. `Relays'l=R(-I) Aand PR'(-) remainrontheirback contactsfthus the'diieriential windings *of `relay, DR `are againclosed in :parallel-'and -iielayDR falls oli and releases relay RSR.Relay :RR "deenergizes relay .RAR .but 'be- `forerslow'release relayRfiR breaks itsfront contacts a circuit is momentarily Vclosedfrombattery, `outer left back contacts o'i relay RSR,` front contacts ofrelay ReR, resistor'R'3 and the 'upper windingof relay HR to ground.yRelay is again energized :and locks up over the Vcalling I `line-thecircuit yofwhicli is now closed with the Ydial at-rest. Anotliercircuitis `also momentarily Yestablished -from ground overtlie leit hand backrcontacts-of relayRSR' and front `contacts `of re-.layRdRtothecountingrelay-s CR. rAssume,for 2 example,- tli-at thecounting relays CIAR, C'ECR, -CRZ andi-GRS are roperated, theaforementioned circuit is ,.completed@over ythe u front --contacts ofrelays ICR3, back `contacts 'of rela-y CR-5,

.back-'contacts-of relayxfIRL resistor R5 and i winding of -lrelay XR@-to batt'ery. Y-Wheii relay RR breaks fits frontv contactsashort-circuitis :removedfromfrelay TRI which locksfupinfseries @with-relay ,X553overa circuit extending from ground, frontcontacts of relay RCR, windingvof Ajrelay II'RI., frontcontactsofrelay XRS and wind- .ing of relayXREtobattery. ,.'It will benoted thatdependent Vupon which `relays CRE.CRlll areenergized, the relays XR! ferent combinations andover theircontacts apply sele'ctivevpotentials PN! (PNUE to vthe bank C of theout-control switch PO. u

RelayfXlft',V for example, connects potential YPN over its front contactand back contacts of relaysXRI VVand XRZ to terminal No. i' in theIbank'C of the out-control switch PO which-is the :counterpart oftheswitchPO in Athe register fcircuit .fully described inmy 'copendingapplicanon. sea Noyer-1,160, 'fue-c1 February :5, y1944.

l XREI are energized singly and Vin dif- Brush C is `connected to thegrid of tube VI of a-pair of testing tubes VI, V2. The grid of tube V2is connected to theh wire which extends over the register nder, theR-link, B-link iinder and B-link to the iirst selector (see Fig. l). Ifthe call is from a main line and relay ER is not energized, on theoperation of relay TRI a circuit is closed over back contacts of relayER for the lower winding of relay FR which grounds the a wire extendingto the rst group selector over brush B of switch PO in its firstposition. When thea wire is grounded the first group selector hunts fora free trunk connected to potential PNS and when such a trunk is grounda gas valve (not shown) associated with the tubes VI and V2 operates andcauses the selector to be arrested, all substantially as described in mycopending application last referred to.

When relay RAR breaks its iront contact the locked up-counting relaysCRE CRIB are released and the dialing circuit o'f the register isrestored'to normal and awaits the dialing of the next digit, which whendialed causes the register to repeat the operations just describedincluding the locking up oi the proper combination of the second .groupof XR relays. All such subsequent digits must of necessity send in thesame initial pulse or pulses so that one of the two first countingrelays CIAR or CIBR, as the case may be, may be locked up until theregister is released. At'the end of the dialing of the nrst digit, ontherelapse of relay R3R but before relay RQR falls off, an obvious circuitis closed `for relay OR which locks up to a front contact of relay RIR.Relay OR opens the energizing circuits of relays CICR and CIDR Ytoprevent operation of these relays when subsequent digits are dialed.

Returning now to the party line identification fc'ircuits: The low'resistance relay SR is included in the locking circuit of the firstcounting relays `zCIARto {CIDR and when energized, upon tne'energizationof relay TRVI places a ground on the starting lead to thefour party line identication circuit (Fig. 8) one of which is requiredfor each party lines or 400 stations. 'Depending upon'whichifirstcounting relays CIAR and 'CIDR are energized, identification potentialsPII `to vPIs are placed on the t wire over theupper low "resistancewinding of relay FR. The identication circuit of Fig. 8 comprises fourtube circuits CTI to CTI-i and associated gas ValvesfGfV, and the gridsof the respective tubes VII areconnected to the four identificationpotentialsPII to IPM. When the starting Vlead X isgrou'nded in Atheregister as described, relay CSR operates, energizes the power magnetfP, and the identication iinder hunts for the t wire uponwhi'ch theregister has placed the PI potential characteristic of the callingstation. When thatpotential has been found the corresponding -tu'becircuit CTI to CTll operates. For example, if station A 'had dialed,identification potential PII would be found on the t wire and the rsttube circuit CTI would operate, Relay GVRI is thereby energized andstops the finder and at the f'sam'c time places a ground on the A brushof 'the identication finder over iront contacts of relay "CSR, backcontacts of relays GVRII, GVRS, 'GVRZ and front contacts of GVRi. Thisgroundon the A brush of the identification finder operates relay PSR! ofthe party line circuit, Fig; 49, over .the left `hand winding of thatrelay which Llocks up to the c wire over its right hand winding inseries with the individual service meter L SM1.' .At the .same time theiirst identification finder T terminal of station A is connected to thet wire with its identifying potential PSI. The negative identifyingpotentials PS are placed on the t wire through a relatively highresistance, whereas the positive identication potentials PI are placedon the t wire through a very low resistance, thereby nullifying theeffect of the PS potentials during the moment that the PI potential isconnected.

Relay GVRl, Fig. 8, closes an energizing circuit for relay GSR whichremoves high tension battery from the gas valve GV to deionize it. RelayGSR also grounds the t wire thereby energizing relay FR, Fig. l0, overits upper winding. Relay FR locks up over its lower winding and removesground from the starting lead X to deenergize relay CSR, Fig. 8, andrelease the identification circuit. Relay FR grounds the t wire and alsogrounds the a Wire to the first group selector over brush B of theout-control switch PO to permit the starting of the selection responsiveto the rst digit. The reason for this is that it is desirable thatselection should not start until the calling station has beenidentified. While the identification circuit serves 100 l-party lines or400 Ll-party line stations, it is extremely rapid in operation and itsholding time averages approximately one second so that the delay due tostation identification is negligible.

Relays PSRZ, PSR3 or PSRA, Fig. 9, are operated when tube circuits GT2,GT3 or GT4 operate responsive to the application of one of thepotentials P12, P13 or P14 to the t wire. Relay GVR2, Fig. 8, isarranged to ground the b wire, whilst relays GVRS and GVRA ground the cwire. Relay PSRZ, Fig. 9, is connected to the b wire Whilst relays PSR3and PSRd are both connected to the c wire. PSRS is made marginal andoperates only when full ground is applied to the C terminal whilst relayPSRll will operate in series with the resistor R. Fig. 8. Thisarrangement is employed since four selections are required and onlythree finder brushes are available over which to exercise such control.

Although the invention has been described in detail as applied to asystem of the kind employing multi-potential selection it is not limitedin its application thereto and it will be obvious to those versed in theart that the broad principles of the invention as claimed in theappended claims may be employed in telephone exchanges employing anytype of selection. Moreover, it is to be understood that the inventionis applicable in cases where any or all of the party lines are eouippedwith two, three or four party line stations.

What is claimed is:

l. In a telephone system, a subscribers line, rst and second party linestations connected thereto, an exchange, selectors at said exchange, asource of current, means for connecting said source of current to saidsubscribers line, impulse transmitters at said rst and second stations,polarized relay means at said exchange, means for connecting saidpolarized relay means to said subscribers line, means comprised in theimpulse transmitter at said first party line station for transmitting animpulse of current having one direction of polarity over saidsubscribers line as the impulse transmitter thereat is set fortransmitting impulses, means comprised in the impulse transmitter atsaid second party line station for transmitting an impulse of currenthaving the opposite direction of polarity over said subscribers line asthe impulse transmitter them* at'is set for transmitting'impulses, meansoperable as said transmitters restore to normal for transmittingnumerical pulses over said subscribers line for controlling saidselectors to extend connection to a wanted line, and means controlled bysaid polarized relay means for determining the identity of the partyline station at which a call is initiated.

2. In a telephone system, a subscribers line, first, second, third andfourth party line stations connected thereto, an exchange, selectors atsaid exchange, a source of current, means for connecting said source ofcurrent to said subscribers line, impulse transmitters at each of saidparty line stations, polarized relay means at said exchange, means forconnecting said polarized relay means to said subscribers line, meanscomprised in the impulse transmitter at said rst station fortransmitting an impulse of positive polarity over said subscribers lineas the impulse transmitter at said rst station is set for transmittingimpulses, means comprised in the impulse transmitter at said secondstation for transmitting an impulse of negative polarity over saidsubscribers line as the impulse transmitter at said second station isset for transmitting impulses, means comprised in the impulsetransmitter at said third station for transmitting two impulses ofpositive polarity over said subscribers line as the impulse transmitterat said third station is set for transmitting impulses, meanscomprised-in the impulse transmitter at said fourth station fortransmitting two impulses of negative polarity over said subscribersline as the impulse transmitter at said fourth station is set fortransmitting impulses, means operable as said transmitters restore tonormal for transmitting numerical impulses over said subscribers linefor controlling said selectors to extend connection to a wanted line,and means controlled by said polarized relay means and responsive tosingle arm double operations thereof for determining the identity of theparty line station at Which a call is initiated.

3. In a telephone system. a subscribers line, rst, second, third andfourth party line stations connected to said line, an exchange,selectors at said exchange, a source of current, means for connectingsaid source of current to said subscribers line, signalling devices ateach of said stations for transmitting signals over said subscribersline for controlling said selectors to extend connection to a wantedline, polarized relay mean at said exchange, means for connecting saidpolarized relay means to said subscribers line, signal means at said rststation for transmitting one impulse of positive polarity over saidsubscribers line responsive to the initiation of a call at said firststation, signal means at said second station for transmitting oneimpulse of negative polarity over said subscribers line responsive tothe initiation of a call at said second station, signal means at saidthird station for transmitting two impulses of positive polarity oversaid subscribers line responsive to the initiation of a call at saidthird station, signal means at said fourth station for transmitting twoimpulses of negative polarity over said subscribers line responsive tothe initiation of a call at said fourth station, said signaling deviceadapted to transmit said signals of positive or negative polarity inadvance of said selective signals for controlling said selectors, andmeans controlled by said polarized relay means and responsive to singleor double operations thereof for determin- :agregarme T13 ing theidentityrofxthe party. line station at which a` call isinitiated.

4. In Va telephone system, a subscribefsfline, `first, and second partyline `stations connected thereto', an exchange, selectors at :saidexchange, :a 'source of alternatingpcurrena meansifor connecting saidsource of alternating current tosaid subscribers line, an `impulsingdevice including ya uni-directional current 4conducting element .at eachparty line station, a pair ,of oppositely :polarized relays at saidexchange, means'for connecting said relays to said subscribers .line at`said exchange, vmeans responsivefto the operation .of theimpulsingdevice at the first Station Afor :sending a i'rstiimpulse `of positivepolarity foll lowed by a predetermined number of further impulses ofalternating polarity over said subscribers'line, means responsive to theoperation of the impulsing device at the second station for sending Yafirst impulse of negative polarity fol- Y,

lowed by a predetermined number of further impulses Yof alternatingpolarity over said 'subscribers line, means controlled by said polarizedrelays for determining `the videntity of the party .line station atwh-ichthe call is initiated, and

`means controlled by said polarized rrelays for `actuating saidselectors.

`5. In a telephone system, a subscribers'` line, first, second, third.and fourth party line stations connected thereto,.` an exchange,selectors .at said exchange, a source of alternating current, .means forconnecting said source of alternating current tosaid subscribersline, animpulsing device in- ,cludinga uni-directional vcurrent conductingelement at each party line station, a pair of -opi f -positely polarizedrelays, means for vconnecting `said pair .of relaystosaid'subscribersline,'means 'responsive to the operation `of :saidimpulsing device atlsaid first station for sending :a rst impulse ofpositive polarity followed nya/.predetermined knumber of Yfurtherimpulses .ofalternating polarity over said subscribers line, meansresponsive to .the operation of said yimpulsing .device at said `second.station for, sending a first impulse vof Vnegative polarity followed bya predetermined number `of vfurther .impulses .of alternating 'polarityover Asaid subscribers line, means respon- -sive vto the-operation ofsaid impulsing device at said third vstation `for sending two impulsesof positive `polarityiollovved rby a predetermined number of further'impulses Yoi alternating polarity over said subscribers line, means.responsive to the operation 'of said impulsing `device at said fourthstation for sending two impulses `of negative polarity followed by apredetermined number of further `impulses of alternating polarity oversaidrsubscribers line, means controlled by said polarized relays andresponsive to single or double operations of each relaydor ,determiningthe identity ofthe party` line Vstation at which the call is initiated,andfmeansfcon'- scribers line, :an impulsing `device including auni-directional current conducting device ateach said station,V a sourceoi alternating current, means for connecting -said source of alternatingcurrent to said impulsing circuit at said register controller, a pair of'polarizedsrelays means `for connecting .said relays .to vsaid`impulsingecircuit at saidregister controller, means responsive :to theoperation-of 'the impulsing `device at the rst station for sending varst impulse ofnpositive polarity followed bya predetermined number o'ffurther impulses of alternating polarity over 4said subscribers line,means responsive to the operation of the impuls'ing device atthe second`station for sending a rst impulse of negative polarity followed by apredetermined number of=iurther impulses of alternating polarity oversaid subscribers line, means controlled by said polarized relaysfordetermining the identity Vof the party line station at which the callisinitiated, and means controlled by said polarized relays foractuating'said digit storing means.

7. In a telephone system, a subscribers line, first, second, third andfourth party line stations connected thereto, a register controllerincluding digit storing means, means for Icompleting an impulsingcircuit between any one of said party line stations andsaid register.controller Aincluding said subscribers line, an impulsing deviceincluding a uni-directional current conducting device at each saidstation, a source of alternating current, means for connecting saidsource of alternating current to said impulsing Vcircuit at saidregister controller, a pair of polarized relays, means forconnectingsaidmelays to said mpulsin-g circuit at Ysaid registercontroller, means-responsive to the operation of said impulsing deviceat said first station forsending a rst impulse of positive polarity-followed by apredetermined number of further impulses of alternatingpolarityV over said subscribers line, means .responsive to the operationof said impulsing device at said second station for sending a firstimpulse :of negative polarity followed by a predetermined number offurther impulses of alternating polarity over said subscribers line,means responsive .to the operation of said impuls- Ying device at saidthird station for sending two impulses of positive polarity followed bya predetermined number of further impulses of alternating polarity oversaid subscribers line, means responsive to the operation of said im-.pulsing device at said fourth station for sending `two impulses ofnegative polarity followed by a Apredetermined number of furtherimpulses of alternating polarity over said subscribersA line,

`means controlled by said polarized relays and responsive to single ordouble operation of "each relay rior determining the identity of theparty line station at which the call is initiated, :and means controlledby said polarized vrelays vfor .actuating said digit-storing means.

8. In a telephone system, a'subscribers line, a

.plurality-of party line stations connected thereto, an exchange, asubscribers line circuit atJsa-id exchange, a plurality of registercontrollers at 'said exchange, means responsive to the initiation Aof acall at one of said party line stations for extending said subscribersline to an idle onerof -said register controllersand for completing atest wire connection from 'said line circuit to the selected,idleregister controller, a Vsource of potential, means vfor connectinga predetermined -potential characteristic of party line service to :saidtest wire atvsaid line circuit, and electronic `'means vin said regstercontroller arranged to re- :spond to said predetermined potential Yformodifying the circuits of said register controller for partylineservice.

19. In a telephone system a vplurality of subscribers lines, party linestations connected t0 each said subscribers line, an exchange, aplurality of register controllers at said exchange, a line circuit foreach subscribers-line including individual service meters for each partyline station on the line, a party line identification circuit comprisinga switch including a set of movable terminals and a set of stationaryterminals one for each said subscribers line, means responsive to theinitiation of a call at any one of said party line stations forconnecting the subscribers line to which it is connected to an idleregister controller, means at each party line station for sending to aselected register controller a signal characteristic of the identity ofsaid party line station means in said register controller responsive tosaid last-mentioned signal for applying to the set of stationaryterminals in said identification circuit switch individual to thecalling subscribers line a marking potential characteristic of thecalling party line station, means for causing the set of movableterminals of said switch to engage said marked set of stationaryterminals, and selective means in said identication circuit arranged torespond to said characteristic marking potential and to prepare acircuit for the service meter individual to the calling party linestation in the subscribers line circuit.

10. An arrangement according to claim 9 where in said selective means insaid party line identication circuit comprises an electron tube testingdevice arranged to respond selectively in accordance with the magnitudeof the marking potential applied to the set of stationary terminals insaid identification circuit switch.

11. An arrangement according to claim 9, wherein said selective means insaid party line identification circuit comprises a plurality of electrontube testing circuits equal in number to the maximum number of partyline stations on any subscribers line each having locally applied to anelectrode thereof a potential of a predetermined magnitude and arrangedto operate` when said marking potential bears a predetermined relationto said potential of predetermined magnitude.

12. An arrangement according to claim 9, further comprising an operatorsidentication finder switch including a bank terminal for each party linestation and wherein means is pro- Vvided for applying the party linestation identication marking potential derived in said registercontroller to the calling station terminal in said operators identicatonfinder switch.

13 An arrangement according to claim 9 further comprising an operatorsidentication finder switch including a bank terminal for each party linestation and wherein means is provided in said subscribers line circuitfor applying a distinctive class of service potential to the respectivebank terminals.

14. An arrangement, according to claim 9 wherein the connection set upbetween said subscribers line and said idle register controller includesa test wire connection and wherein means is provided in said registercontroller for applying said marking potential characteristic of thecalling party line to said test wire.

15. An arrangement according to claim 9, further comprising an operatorsidentication nder switch including a bank terminal for each party linestation; and means for connecting the said bank terminal of a callingparty line station to the calling party line circuit under the controlof said selective means in said identifica- ,tion circuit.

'16. In a telephone system a plurality of subscribers lines, party linestations connected to each said subscribers line, an exchange,Y a,plurality of register controllers at said exchange, a line circuit foreach subscribers line, a party line identication circuit comprising aswitch including a set of movable terminals and a set of stationaryterminals one for each said subscribers line, means responsive to theinitiation of a call at any one of said party line stations forconnecting the subscribers line to which it is connected to an idleregister controller, means at each party line station for sending to aselected register controller a signal characteristic of the identity ofsaid party line station, means in said register controller responsive tosaid last-mentioned signal for applying to the set of stationaryterminals in said identication circuit switch individual to the callingsubscribers line a marking potential characteristic of the calling partyline station, means for causing the set of movable terminals of saidswitch to engage said marked set of stationary terminals, selectivemeans in said identication circuit arranged to respond to saidcharacteristic marking potential, an operators identication finderswitch including a bank terminal for each party line station and meansfor connecting the said bank terminal of a calling party line station tothe calling party line circuit under the control of said last-mentionedselective means.

17. In a telephone system a plurality of subscribers lines, party linestations each including an impulse transmitter connected to each saidsubscribers line, an exchange, a plurality of register controllers insaid exchange, a line circuit for each subscribers line includingindividual service metering means for each party line station on theline, means responsive to the initiation of a call at a party linestation for connecting the subscribers line to which it is connected toan idle register controller over a pair of impulsing wires and a testwire, means included in said impulse transmitters for sending over saidimpulsing wires to said selected register controller signalscharacteristic of their identity, means in said register controller forapplying to said test wire a predetermined marking potentialcharacteristic of the identity of a calling station, a party lineidentication circuit comprising a nder switch having a set of terminalsincluding a test terminal for each said subscribers line, means forapplying the said predetermined characteristic marking potential derivedin said register controller to the said test terminal particular to thecalling subscriberTs line, means for moving said finder switch to engagesaid marked test terminal, and selective means in said party lineidentification circuit arranged to respond to said characteristicmarking potential and to prepare a circuit for said service meteringmeans individual to the calling party line station.

18. An arrangement according to claim 16 comprising a metering relay ineach said subscribers line circuit for each party line station connectedto said line and conductors extending from said metering relays to theindividual terminals of a set of terminals in the bank of saididentification circuit iinder switch, and wherein said selective meansin said party line identication circuit is arranged to close circuitsover said conductors to selectively actuate said metering relays.

19. In a telephone system, a subscribers line, a plurality of party linestations connected theresaid identification circuit characteristic ofthe identity of the calling party line station to operate said selectivemeans, and means for preparing the circuit of a service meter individualto the calling party line station under the control of said selectivemeans.

20. In a telephone system, a subscribers line, a plurality of party linestations connected thereto, an exchange, a source of alternatingcurrent, means for connecting said Ysource ofV alternating current tosaid subscribers line, an

impulsing device including a rectifier at each A party line station, aringer at each party line station normally connected to said line,polarized relay means at said exchange, means for con-v necting saidpolarized relay means to said subscribers line, means for intermittentlyreversing the direction of polarity of the rectifier in said subscribersline at a calling party line station so as to send alternate trains ofpositive and negative impulses thereover, and means for providing aneffective short circuit to the ringer at other party line stations onsaid line for said trains of positive and negative impulses and fortheir complementary half cycles.

GERALD DELAKIN.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 2,277,206 Cesare et al. Mar. 24,1942 2,281,508 Lundstrom Apr. 28, 1942 2,306,173 Logan Dec. 22, 19422,326,679 Retallack Aug. 10, 1943 2,347,108 Hubbard Apr. 18, 19442,406,001 Deakin Aug. 20, 1946 2,410,520 Ostline Nov. 5, 1946

